大鳍鳠臀鳍和脂鳍的比较组织学研究

Comparative and histological studies on the anal and adiposefins in freshwater catfish Mystus mecropterus (Bleeker)

大鳍鳠臀鳍和脂鳍均是皮肤特化的产物．臀鳍的组织结构可分为表皮层、胶原纤维层、胶原下层和鳍条４部分；脂鳍可分为表皮层、胶原纤维层和脂肪层．臀鳍和脂鳍的表层均与皮肤的表皮相似，而发达的胶原纤维层与皮肤真皮的致密层相当．臀鳍的胶原下层、脂鳍的脂肪层与皮下层相当，而鳍条则是矿化的结缔组织．从特化程度来看，脂鳍的特化程度不如臀鳍高，表明脂鳍应是奇鳍褶的痕迹器官．

Mystus macropterus (Bleeker)(Bagridae,Siluriformes)has well developed adipose fin.The analfin is divided into epidermis,collagen fiber stratum,subcollagen fiber stratum and fin ray, while theadipose fin is composed of epidermis,coliagen fiber stratum and adipose.stratum.Both adipose and an nal fins were derived from skin,the epidermis of adipose and anal fins were basically the same as theepidermis of teleostean skin,and the developed collagen fiber stratum was equivalent to the stratum subcutaneum of skin, and fin ray was highly specialized and mineralized fibrous connective tissue.The median fins and adipose fin are ontogenitically homolosgous, but the adipose fin is less specialized than analfin and seems to have no importance in Storing fat because it is too small in size,and adipose fin degenerates completely during postemboryonical development in some species of Siluriformes such as Silurus asotus.Therefore,it is suggested that the adipose fin of M.macropterus is only a vestigial organ of medianfins.